1. Field of the Invention
This invention relates generally to the field of concrete crushing, rock crushing, mining, and recycling of concrete and other materials, and specifically to a concrete crushing plant transportable over highway systems to construction and demolition sites.
2. Description of the Related Art
Portable crushing plants for rock, concrete and other demolition materials have been developed for applications where the quantity of material to be crushed at a particular site is limited. Highway portability is important, for example, in non-mining applications such as in building demolition or in clearing the wreckage following a natural disaster, such as an earthquake. However, high capacity machinery in a typical plant, rated in tons per hour, can often exceed the legal weight limits specified by the federal or state government for its roadways. This situation has been overcome, in part, by breaking down the plant into subcomponents that are separately transported to a new site and then reassembled. Typically, where the crusher is fed with a vibratory hopper/feeder, it has been a custom in large capacity plants to transport the vibratory hopper/feeder separately on a general utility trailer. At a new site, a heavy crane is used to lift the hopper/feeder from the transport trailer onto the framework of the main part of the plant. When a job is completed, this set-up process is reversed again using a heavy crane to lift the hopper/feeder from the main structure to a utility trailer. This set-up procedure, although commonly used, is very costly because of crane rental charges incurred at the beginning and end of a job. When a plant is only at a location for a short period of time, the crane rental charges can greatly increase the overall cost of the job.
Various crushing apparatus are shown in U.S. Pat. No. 4,383,651 to Couperus, U.S. Pat. No. 4,585,179 to Tsuji, U.S. Pat. No. 4,598,875 to Bronson, U.S. Pat. No. 4,655,402 to Desourdy, U.S. Pat. No. 4,881,691 to Oldengott, U.S. Pat. No. 4,951,885 to Thus, U.S. Pat. No. 5,026,205 to Gorski, and U.S. Pat. No. 5,161,744 to Schoop, all incorporated herein by reference.